1. Technical Field
The present application relates to a beverage bottling plant for filling bottles with a liquid beverage having a filling machine as described herein below.
2. Background Information
A beverage bottling plant for filling bottles with a liquid beverage filling material can possibly comprise a beverage filling machine with a plurality of beverage filling positions, each beverage filling position having a beverage filling device for filling bottles with liquid beverage filling material. The filling devices may have an apparatus designed to introduce a predetermined volume of liquid beverage filling material into the interior of bottles to a substantially predetermined level of liquid beverage filling material. The apparatus designed to introduce a predetermined flow of liquid beverage filling material further comprises an apparatus that is designed to terminate the filling of the beverage bottles upon the liquid beverage filling material reaching the predetermined level in bottles. There may also be provided a conveyer arrangement that is designed to move bottles, for example, from an inspecting machine to the filling machine. Upon filling, a closing station closes the filled bottles. There may further be provided a conveyer arrangement configured to transfer filled bottles from the filling machine to the closing station. Bottles may be labeled in a labeling station, the labeling station having a conveyer arrangement to receive bottles and to output bottles. The closing station and the labeling station may be connected by a corresponding conveyer arrangement.
On filling machines for filling containers such as bottles, cans, canisters etc., it has been known for a long time that before the filling, the containers to be filled can first be treated with a vacuum and an inert gas such as CO2 or steam, for example. The purpose of this flushing is to reduce the germ content and oxygen content inside the containers.
For reasons of health and to increase shelf life, this process is customarily used in the bottling of liquids that are bacteriologically critical and/or oxygen-sensitive. The gases that must thereby be removed from the containers are generally removed via separate gas paths or ducts.
In addition to the use of separate gas paths or ducts, the prior art also describes configurations in which the gas is removed from the containers using what is termed a return gas pipe.
These return gas pipes, which in numerous configurations of filling machines are also used to exhaust the gas that escapes during the filling process from the containers being filled, generally empty into the storage reservoir for the goods being bottled, where they end above the fluid level in said storage reservoir.
In configurations of this type, in which ambient air, or at least the flushing gas that has been in contact with the container comes directly into contact with the liquid being bottled, there is necessarily an increased risk of contamination of the goods being bottled. This risk is particularly high if the return gas and the goods being bottled come into contact with each other over large areas.
DE 37 31 759 discloses the location on the peripheral surface of a ring bowl of a plurality of separate filling mechanisms that have a defined liquid volume to hold the liquid being bottled and a gas space that is located above the liquid being bottled. In this apparatus of the prior art, the respective return gas tube ends inside this separate filling mechanism. In this configuration, of course, the return gas initially comes into contact only with the volume of liquid being bottled that is located in the filling mechanism itself, as a result of which the risk of contamination is reduced, although it is impossible to fully rule out a more serious contamination of the liquid being bottled, because the return gas from any filling mechanism can travel through a large-diameter passage opening into the ring bowl.
DE 39 28 009 describes a filling machine with a separate return gas duct that is located above the storage reservoir. In this device, the return gas is transported via an additional shuttle valve either into the storage reservoir for the liquid being bottled and/or into the return gas duct. DE 39 28 009 also teaches that the pressure in the return gas duct is set lower than the pressure in the storage reservoir. Because of the shuttle valve that is provided and the different pressure settings, however, such a device is mechanically complex and expensive to manufacture.